This invention relates to improvements in ovens and transporting systems for ovens for the curing of sealants and baking of lacquers applied to ends for containers such as cans.
Easy-opening can ends of the push-in type, such as those described in Australian Pat. Nos. 444,068, 518,940, 523,783, 528,006 and Application No. 61388/80 require discrete areas of sealant to be applied in the region of the edges of the push-in tabs to hermetically seal the can end. Sealant is usually applied to discrete areas covering the cut edges of the tabs and openings, for example by the system described in Australian Pat. No. 477,562.
In the case of so-called "ring-pull ends", it is sometimes necessary to apply repair lacquer to the can end in the region of the score defining the tab and this lacquer is usually subsequently baked to drive off volatiles.
Where easy-opening can ends of the push-in type are manufactured from steel, it is desirable to protect the shorn edges of the opening(s) formed by the end conversion process and this may be done by spraying repair lacquer or some other form of repair coating onto the can end in that region of the end. This protective material must similarly be baked to drive off volatiles and to ensure that the lacquer is substantially dry before the can ends are stored or packaged for future use.
Until the present invention, ovens used in the can manufacturing industry have been extremely large, inefficient and not particularly suited to the efficient curing of sealant applied to push-in tab ends or to the efficient baking of repair lacquer applied to such ends. Known ovens not only occupy much valuable floor space in a can manufacturing plant but also cause the surrounding areas of the plant to be undesirably heated making it uncomfortable for the plant operators.